In a large bowl, combine the chicken meat and bones, chiles, garlic, cilantro sprigs, bay leaves, lime zest and 1 teaspoon salt. Toss until well mixed.

Heat 1 tablespoon oil over medium heat in a large Dutch oven or casserole. Add the onion and 1/2 teaspoon salt and cook, stirring occasionally, until translucent and tender, about 5 minutes. Add the curry and cook, stirring, for 1 minute. Add the tomatoes and cook for 1 minute, stirring.

Add the chicken stock, water, and chicken with its seasonings. Raise the heat to high. As soon as the liquid comes to a boil, lower the heat immediately. Adjust the heat to maintain a bare simmer, skimming any foam and scum from the surface.

In a small skillet, heat the remaining tablespoon oil over medium heat. Add the cumin seeds and whisk for 1 minute. Add the flour and turmeric and whisk for 1 minute, then whisk in 1/4 cup of the hot chicken liquid. Cook for 1 minute, whisking, then stir the mixture into the simmering soup. Cook until thickened, about 5 minutes, then season to taste with salt. Garnish with cilantro and serve. Serve with basmati rice.